1. Field of the Invention
The present invention relates in general to the monitoring of nuclear waste, and in particular to a new and useful radiation detector using scintillating optical fiber.
2. Description of the Related Art
Monitoring of sites where high or low level nuclear wastes or nuclear materials are stored is becoming increasingly common. Due to the questionable integrity of storage containers, the frequent monitoring of soil and ground water at such sites is required. These monitoring methods usually involve drilling one or more test wells, and then instrumenting the test wells with laboratory radiation detection equipment adapted for field use, such as scintillation chambers and photomultiplier tubes. Drilling of the test wells is expensive and introduces the potential for cross-contamination of geological strata. The instrumentation after adaptation for drilling is expensive and requires high voltage lines for operation in the well, and thus is not generally suitable for applications requiring a large number of monitoring locations.
The use of optical fiber bundles to transmit light from scintillators to photomultiplier tubes is known in the art. This method is often used when the local environment at the scintillator location is too hostile for direct installation of the photomultipliers. Recently, optical fibers have been developed which incorporate scintillating dopants in the fiber structure. These fibers are sensitive to the same particles and types of radiation as conventional scintillators, and are used primarily as imaging detectors in radiographic systems for replacing phosphor screens and in detection applications such as neutron long counters.